Draft PPS18: Renewable Energy
Annex 1 Technology: Siting Issues
G11. For best performance, solar water heating collectors need to be inclined at an angle of 30-40 degrees, depending on the latitude, and orientated facing due south. In practical terms, this is not always possible on existing buildings, and some degree of flexibility in inclination and orientation is acceptable although this will be at the expense of best performance. To function satisfactorily collectors can be inclined at between 10 and 60 degrees, and orientated facing from east to west (i.e. within 90 degrees of due south).
G12. Although roof mounted collectors are the most common, they can also be mounted on the sides of buildings, or on free standing support structures on the ground. The latter is particularly common in the case of swimming pool heaters.
G13. Shadows from buildings, trees or other structures can significantly reduce performance of solar hot water collectors, and planners and designers should take reasonable steps to minimise overshadowing.